To enable facilitation of mounting of a grounding wire thicker than a signal wire to prevent the signal wire or the grounding wire from being mismounted, and to improve the fixed part of the signal wire or the grounding wire in durability.

A performance board 10 is equipped with one or more signal wire through-holes 11 connected to a signal wire 1, and one or more grounding wire through-holes 12 connected to a grounding wire 2. The grounding wire through-hole 12 is set larger in area than the signal wire through-hole 11. Furthermore, the signal wire through-holes 11 are each formed in a circle, and the grounding wire through-holes 12 are each formed into a square, which is as large in size as the one with the signal wire through-hole 11 inscribed therein. When a plurality of signal wire through-holes 11 and a plurality of grounding wire through-holes 12 are provided, the signal wire through-holes 11 and the grounding wire through-holes 12 are arranged alternately.